Which concept was NOT a part of Kepler's Laws of Planetary Motion?
A) All planetary orbits are ellipses.
B) The square of the planet's period is equal to the cube of its average distance.
C) A planet must move fastest in its orbit at perihelion.
D) Epicycles are needed to explain the varying brightnesses of the planets.

Question

Quizplus · Accepted Answer

Kepler's Laws of Planetary Motion do not involve the concept of epicycles, which were part of the geocentric model of the Solar System developed by earlier astronomers such as Ptolemy. Kepler's laws instead describe the motions of planets in a heliocentric (Sun-centered) model.

Which Concept Was NOT a Part of Kepler's Laws of Planetary